AbstractNitric oxide (NO) has a fundamental role in the plant hypersensitive disease resistance response (HR), and S‐nitrosylation is emerging as an important mechanism for the transduction of its bioactivity. A key step toward elucidating the mechanisms by which NO functions during the HR is the identification of the proteins that are subjected to this PTM. By using a proteomic approach involving 2‐DE and MS we characterized, for the first time, changes in S‐nitrosylated proteins in Arabidopsis thaliana undergoing HR. The 16 S‐nitrosylated proteins identified are mostly enzymes serving intermediary metabolism, signaling and antioxidant defense. The study of the effects of S‐nitrosylation on the activity of the identified proteins and its role during the execution of the disease resistance response will help to understand S‐nitrosylation function and significance in plants.